多重聚合酶链反应检测革兰阳性／阴性细菌、真菌和mecA基因的临床评价

目的：评价多重聚合酶链反应（PCR）直接检测革兰阳性／阴性细菌、真菌和耐甲氧西林葡萄球菌（MRS）的可靠性和准确性。方法：采用细菌16rRNA基因通用引物、革兰阴性细菌特异引物、全真菌通用引物和mecA基因特异引物，通过多重PCR对271份临床无菌性体液扩增检测革兰阳性／阴性细菌、真菌和MRS，同时对这些标本进行细菌、真菌培养和甲氧西林对葡萄球菌MIC测定。结果：多重PCR诊断无菌性体液体革兰阳性／阴性细菌、真菌和MRS感染的特异性、灵敏度、阳性预测值、阴性预测值和诊断效率分别为98.5％、97.0％、97.0％、99.0％、98.2％、99.1％、95.9％、95.9％、99.1％、98.5％、99.6％、100％、83.3％、100％、99.6％、100％、48.0％、100％、61.8％、71.7％。结论：多重PCR直接检测无菌性体液中革兰阳性／阴性细菌、真菌和mecA基因所致的MRS具有敏感、快速、特异、准确的优点，是一种可靠的实验诊断手段，但不能代替培养法。

Clinical evaluation of multiplex PCR for identification of gram-positive or gram-negative bacteria,fungi and methicillin-resistant staphylocucci in sterile body fluids

Objective To evaluate accuracy and reliability of multiplex polymerase chain reaction(multiplex PCR) for direct detection of bacteria, fungi and methicilin-resistant staphylococci (MRS) in sterile body fluids.Methods These organisms in 271 clinical sterile they fluids were detected by multiplex PCR with bacterial universal 16SrRNA gene primers,gram-negative specific primers, panfungal universal primers and mecA gene specific primers. Meanwhile, bacteria and fungi in these sample were detected by culture method, the MICs of methicillin for the staphylococci were also examined by brothdilution method. results Specifity, sensitivity, positive and negative predictive values and diagnostic efficiency of multiplex PCR for diagnosing gram-positive bacteria, gram-negative bacteria, fungal and MRS infections were 98.5%, 97.0%, 97.0%, 99.0%, 98.2.%, 99. 1%, 95 .9%, 95.9%, 99. 1%, 98.5%, 99.6%, 100%,83. 3 %, 100%,99. 6%, 100%, 48. 0%, 100%, 61. 8%, 71. 7% .Conclusion The multiplex PCR is a sensitive, specific, fast and accurate method for gram-positive or negative bacteria, fungi and MRS mediated by mecA gene detection in clinical sterile body fluids, but it should not substituted for culture method clinically.